bootm: Pass image buffer to boot_get_fdt()

Rather than having boot_get_fdt() calculate this, move the calculation
into the caller. This removes the access to argv[0] in this function,
so we can later refactor it to just accept argv[2] instead of the whole
argv[].

Move the function comment to the header file and fix the u8 argument,
while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/boot/image-fdt.c b/boot/image-fdt.c
index f10200f..6ff2d52 100644
--- a/boot/image-fdt.c
+++ b/boot/image-fdt.c
@@ -447,43 +447,17 @@
 	return 0;
 }
 
-/**
- * boot_get_fdt - main fdt handling routine
- * @argc: command argument count
- * @argv: command argument list
- * @arch: architecture (IH_ARCH_...)
- * @images: pointer to the bootm images structure
- * @of_flat_tree: pointer to a char* variable, will hold fdt start address
- * @of_size: pointer to a ulong variable, will hold fdt length
- *
- * boot_get_fdt() is responsible for finding a valid flat device tree image.
- * Currently supported are the following ramdisk sources:
- *      - multicomponent kernel/ramdisk image,
- *      - commandline provided address of decicated ramdisk image.
- *
- * returns:
- *     0, if fdt image was found and valid, or skipped
- *     of_flat_tree and of_size are set to fdt start address and length if
- *     fdt image is found and valid
- *
- *     1, if fdt image is found but corrupted
- *     of_flat_tree and of_size are set to 0 if no fdt exists
- */
-int boot_get_fdt(int flag, int argc, char *const argv[], uint8_t arch,
-		 struct bootm_headers *images, char **of_flat_tree, ulong *of_size)
+int boot_get_fdt(void *buf, int flag, int argc, char *const argv[], uint arch,
+		 struct bootm_headers *images, char **of_flat_tree,
+		 ulong *of_size)
 {
-	ulong		img_addr;
 	ulong		fdt_addr;
 	char		*fdt_blob = NULL;
-	void		*buf;
 	const char *select = NULL;
 
 	*of_flat_tree = NULL;
 	*of_size = 0;
 
-	img_addr = (argc == 0) ? image_load_addr : hextoul(argv[0], NULL);
-	buf = map_sysmem(img_addr, 0);
-
 	if (argc > 2)
 		select = argv[2];
 	if (select || genimg_has_config(images)) {